BRUSSELS (AP) -- The Latest on the poisoning of a Russian ex-spy and his daughter in Britain (all times local):

7:25 p.m.

German Chancellor Angela Merkel says there's serious information pointing to Russia's responsibility in the poisoning in Britain of a Russian ex-spy and his daughter, and that the duty now lies with Moscow to prove that it wasn't involved.

On a visit to Warsaw, Merkel also has said she expects European Union leaders to come to "strong conclusions" in the matter at a summit later this week in Brussels. Russia strongly denies any involvement.

Merkel spoke during a news conference alongside Poland's prime minister, who said European leaders must show solidarity after the nerve agent poisoning of ex-spy Sergei Skripal and his daughter Yulia.

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6:10 p.m.

British military officials say a vehicle has been removed from a village 10 miles (16 kilometers) north of Salisbury as part of the inquiry into the poisoning of a Russian ex-spy and his daughter.

A road in the village of Durrington was closed off and tents were erected as the military and police searched for clues Monday. The Ministry of Defense said the military presence was "part of our ongoing support to help police in the investigation."

Ex-spy Sergei Skripal and his daughter Yulia remain in critical condition in a Salisbury hospital more than two weeks after the March 4 attack.

The military did not say why the vehicle was removed. British media say it had been used to transport Yulia Skripal from the airport when she arrived in Britain a day before the attack.

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5:30 p.m.

NATO's secretary-general says the alliance stands united with Britain amid diplomatic tensions with Russia over an ex-spy's poisoning in an English city.

Jens Stoltenberg said "all 29 NATO allies stand united. We stand in solidarity with the United Kingdom. The U.K. is not alone." He made the comments during a joint news conference with U.K. Foreign Secretary Boris Johnson at NATO headquarters.

Britain has accused Russia of being behind the March 4 attack in Salisbury with a Novichok nerve agent on ex-spy Sergei Skripal and his daughter that has left them in critical condition. Moscow vehemently denies any involvement.

Stoltenberg said that "Russia's response so far has demonstrated a clear disregard for international peace and security. We continue to call on Russia to provide the complete disclosure of the Novichok program."

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12:05 p.m.

The Kremlin says Britain will eventually have to offer proof to back up its claim of Russia's involvement in the poisoning of an ex-spy - or apologize.

President Vladimir Putin's spokesman, Dmitry Peskov, said that the "slanderous anti-Russian flow coming from Britain is inexplicable, unfounded and driven by unclear motives."

He told reporters that Britain will have "to back it with some kind of proof or offer excuses."

Britain has accused Russia of using a military-grade nerve agent to poison former Russian double agent Sergei Skripal and his daughter, who have been in critical condition for two weeks. Britain has announced the expulsion of 23 Russian diplomats, and Russia has responded in kind.

The European Union on Monday condemned Skripal's poisoning, and British Foreign Secretary Boris Johnson dismissed Moscow's denials as absurd.

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10 a.m.

British Foreign Secretary Boris Johnson is describing Russian claims that it is not responsible for the poisoning of a former spy as absurd, and says the U.K. has the full backing of its European partners.

Johnson told reporters in Brussels Monday that "Russian denials grow increasingly absurd," with contradictory claims about whether Russia produced the nerve agent Novichok used in the March 4 attack that left Sergei Skripal and his daughter in critical condition.

He said "what people can see is that this is a classic Russian strategy of trying to conceal the needle of truth in a haystack of lies and obfuscation."

Johnson, speaking before briefing European Union foreign ministers on developments, said many in the bloc have been victims of "malign Russian behavior" and that Moscow is "not fooling anybody anymore."